Some digital broadcast receivers have a recording function for recording a program being watched and a function, called a still image capture function, for recording one scene of a program. However, in terms of protection of copyright, protection of interests of a program creator (content holder) and the like, digital broadcast program content is controlled based on copy control information embedded previously by the program transmission side. For example, the digital broadcasting is operated currently using a so-called copy once or copy never scheme that places restrictions on copying a recorded program from a primary storage destination (a DVD recorder) to a secondary storage destination (an HDD, etc.). This copy control information is set by a content provider and a service provider who provide program content. These copy controls such as the copy once and copy never according to the conventional art can be carried out by copy control descriptors in the PMT (Program Map Table) in the case of digital broadcasting, for example. Further, in the case of BS/CS digital broadcasting and the like, there are some cases of scrambling broadcast signals to apply restrictions on copying. For example, controls are performed so that some contents can be watched for free without being scrambled and some contents that are required to be paid are scrambled and can be watched only by a user who pays to obtain key data for descrambling the contents.
In addition, the still image capture function has a function similar to the recording function in respect of recording one frame of video, and thus is subjected to restriction by the copy control information in the same manner as the recording function. Further, as to the still image capture function, the user who is watching a program captures (records) video by performing recording operations using this function at any timing. However, the user needs to watch a screen all the time to capture, which impairs usability. Further, there may be some cases where capture cannot be performed at a timing desired by the user due to a time lag for the capture operation. On the other hand, in order to present a scene desired by the user from the video data that has been captured previously, there is a technique for performing capture based on the presentation time (time stamp) of the video to find the video data corresponding to the presentation time specified by the user (see Patent Document 1). Relating to this conventional art, in order to solve the above problem that the user needs to watch a screen all the time, for example, there is a method for programming a recorder to record and store a part of the video such as one scene or one frame of the video in advance. As an example, when the user wants to record only one part, such as one scene or, for example, one song of a music program, there has been considered a method for programming a recorder to record content by specifying the channel No., the time to start recording and the time to finish recording. However, since broadcasting is one-directional transmission, it is impossible to recognize previously the point of still image the user wants to capture. Therefore, it is highly likely that, even if time is specified finely such as by the minute, a desired video or one frame of the video cannot be captured.
As mentioned above, in the present circumstances, although copying program content that has been recorded (video and audio recording) is controlled, recording of program content in real time and video capture are not prohibited. However, in the future, recording in real time or capture may be restricted with the introduction of pay-TV into the terrestrial digital broadcasting or depending on operation of each broadcast station. In that case, with the existing standard by the ARIB (Association of Radio Industries and Businesses), that is, a scheme in which copy control descriptor is included in the PMT, the restriction range of recording can be specified only at a program level, that is, an ES (Elementary Stream) level. Because of this, a content holder or a service provider cannot utilize flexible recording restrictions such as recording of one portion or capture of a certain one scene of a program. In other words, a viewer cannot record a CM in a program prohibited from being recorded and the useful information for the viewer such as a giveaway entry address that is broadcasted as a part of the program. Thus usability is impaired. Further, it has a problem that a program creator cannot get advantages from recording of the information by the user (the CM goods will be known in the market).
It is obvious that if the real-time recording is prohibited, capture of a still image of a program that is prohibited from being recorded is also prohibited in the same manner. Even if recording one portion of a program is allowed, a user cannot program a recorder to record the portion by specifying the time as in the above case unless the information thereof is provided to the user previously. In other words, even if the user programs the recorder to record a portion of a certain program by specifying (program) the time, there is a concern that broadcasting hours of a program scheduled before the program to record may be extended and the programmed time is thus different from the broadcasting hours of the program the user wants to record. Consequently, the portion corresponding to the specified time may span the portion which is prohibited from being recorded. For example, if the programmed time period for recording is set longer, the desired portion permitted to be recorded can be recorded. However, the portion prohibited from being recorded cannot be recorded properly and recorded, for example, as a black screen or as a scrambled screen, which will not only become an eyesore to the user but also occupy memory of the recording apparatus wastefully, and thus it is unfavorable.
Patent Document 1: Japanese Patent Application Laid-Open No. 2004-080476